Sponge mophead and attaching clips



Nov. 26, 196s J, G'., SMON 3,412,416

SPONGE MOPHEAD AND ATTACHING CLIPS v Filed July 3l, 1967 F/GJ I NVENTOR.

United States Patent O 3,412,416 SPONGE MOPHEAD AND ATTACHING CLIPS John G. Simon, St. Paul, Minn., assignor to Minnesota Mining and Manufacturing Company, St. Paul, Minn., a corporation of Delaware Filed July 31, 1967, Ser. No. 657,258 6 Claims. (Cl. 15-118) ABSTRACT F THE DISCLOSURE A sponge mophead adapted for attachment on the mounting plate of a mop frame by means of two separable attaching clips having prong means piercing the prismatic sponge body.

Specification This invention relates to cleaning implements and particularly to sponge mops and in one aspect to a replaceable sponge mophead and to attaching clips for securing the same to the base plate of a sponge mop frame.

Sponge mops have become widely used by housewives. Basically these mops involve a synthetic sponge, typically a block of regenerated cellulose, having a base plate adhesively bonded to the upper surface and provided with means for attachment to the mounting plate onva mop frame. The sponge and base plate constitute a head which after extended use is replaceable by a new mophead thus restoring the mop. The base plates of the sponge mopheads are provided with either holes, longitudinally extending slots or slide means which coincide with the holes or other attaching means on the mounting plate of the mop frame.

Exemplary mopheads of the aforementioned type are illustrated in U.S. Patents Nos. 2,594,553, 2,663,042, and 3,188,676.

To install a new mophead of the latter type on the mop frame the slide attaching means on one side of the mophead is mounted on the tab on the mounting plate of the mop frame and then the sponge head is compressed longitudinally permitting the slide on the opposite side of the mophead to be fitted over the tab on the opposite side of the mounting plate. The return of the sponge to its normal position places the tabs and slides in cooperating relationship to hold the mophead on the mop frame. This requires that the sponge be moist and flexible to permit assembly.

It will be noted from a study of the art that in substantially all these devices the attaching .means for the mophead comprise continuous metal plates, separate plates, and/or exible (fabric) backings to form the base plate and the base plates are all adhered to a face of the sponge material. In order to get a good bond between the sponge and the base plate the sponge material must be at least partially dried. Usually heat presses are used for this operation. It is an extensive and expensive operation requiring the application of adhesive, precise positioning of the backing plate, and the application of heat and pressure for a time sufficient to dry the sponge at the bonding surface and cure or -dry the adhesive to gain the requisite bonding. During the bonding good control of the sponge is necessary because upon drying the sponge material the resulting effect on the dimension and character of the face, to which the backing plate is bonded, is not assured. Then, after the bonding operation, the sponge must be redampened to gain a certain percentage moisture. This moistening is necessary before or after packaging the sponge so it will have a soft character attracting the customer and a natural resilience permitting its mounting on the mop frame by the user without breaking the sponge, as would happen if the same were sold bone dry. Other disadvantages, besides expensive, when an adhesive operation is required are the unsightly adhesive flash on the product, objectional solvent odor and fire hazard during manufacture, the selection of adhesive limits use of mop, etc.

The problem of producing an inexpensive and economical product is further increased when it is necessary to bond m-etal fabric base plates to the Sponges, the bodies of which Sponges have a laminate of low density fibrous lofty abrasive mat on one face thereof. This abrasive product is secured in a thin layer to the sponge during manufacture. After the sponge and the laminated mat are produced, the same must be exposed to the extensive bonding operation to have the base plate bonded thereto by an adhesive. The bonding is faster when the sponge is relatively dry (l0 to 16% moisture as opposed to 60% when manufactured) but in this dry state the sponge faces are often uneven and warped because of the fact that the mat does not dry and shrink in the same manner as the sponge body. Therefore, to have an attractive and an economical product (a sponge mophead with an abrasive mat laminate) it is necessary to produce a sponge mophead which may be attached to the frame of a sponge mop without the costly operations of bonding a backing plate to the sponge. This necessarily involves the need for a different attaching means for the mopheads but one which will still fit existing commercially available sponge mop frames to eliminate the expense of replacing existing mop frames to utilize the new mophead and yet make the mopheads generally less expensive.

The present invention thus provides a novel sponge mophead which may be attached to the common types of sponge mop mounting frames presently in use and to provide a sponge mophead with a lower manufacturing cost without diminishing the utility or the life of the same.

The present invention provides a sponge mophead having a laminated abrasive mat on one face which is lower in cost than a similar sponge mophead utilizing the attaching means presently known in the art.

The present invention provides a novel attaching means for sponge mopheads to existing sponge mop mounting frames.

The present invention also provides an attaching means which may be utilized repeatedly with sponge mopheads, thus eliminating the need for replacement of part of the attaching means for the mop frame each time a replacement head for the mop is purchased. An example of the prior use of a clip type member for securing a mophead to a mop frame is shown in U.S. Patent No. 2,708,283. This device utilizes a fabric backing sheet sec-ured to the sponge to cover grooves in the sponge material. The grooves served to receive arms of a clip which fastened the sheet and sponge to a mop frame mounting plate. This device like the aforementioned types, however, still requires the objectionable adhesively secured material to the sponge body.

The present invention provides a new sponge mophead and attaching clip. The sponge mophead comprises a prismatic sponge body having two ends and a plurality of rectangular sides. The ends of said body are formed with slots which permit the insertion of prong means which hold the sponge body to the =mop frame. The prong means are part of a clip, attachable to the sponge body, having a generally U-shaped conguration with attaching means on one ange adapted for connection to one or various types of mop frame mounting plates.

The above and further features and advantages of the present invention will be more apparent after reading the following description which refers to the accompanying drawing wherein:

FIGURE 1 is a plan view of a mophead and attaching means formed in accordance with the present invention;

FIGURE 2 is a fragmentary perspective view showing the sponge body and attaching clipV in separated relation;

FIGURE 3 is a fragmentary vertical sectional view showing an attaching clip and sponge body in assembled relationship; and

FIGURES 4 and 5 are perspective views of modifications of the attaching clip.

In the drawing, a prismatic sponge body 6 (having a pair of ends 7 and 8 and a number of sides 9, 11, 12, 13, and 14) has secured to the side 12 thereof a low density fibrous lofty abrasive mat 16. The sponge body 6 has a greater axial length than width or thickness but provides a relatively Wide face side 9 which covers the mounting plate of a sponge mop frame when the mophead is secured to most commercial household sponge mop frames.

Positioned above each end of the face side 9 are attaching means which cooperate with the attaching means formed on the mounting plate of the mop frame to secure the sponge body thereto. The attaching means is affixed to the sponge body by means of generally U-shaped sheet metal or plastic molded clips, illustrated generally by the reference numeral 18. The clips 18 are joined to the sponge body by means of a number of narrow thin slits or slots formed by cutting the sponge. As noted in FIG- URE 2 at the end 7 the sponge body has a plurality of slots 19 and 21 which are narrow thin slots positioned in spaced relation below the surface of the face side 9, and extend generally parallel to the surface 9 and axially of the sponge body (see FIGURE 3). The slots are located below the surface 9 a distance adequate to resist tearing out and spaced from the surface 13 such as not to decrease the life of the head. In a sponge body having (when new) a thickness of one and three-fourths inches on the front side (12) and approximately one inch on the back side (14), the slots are about one-fourth inch from the face side 9.

The clips 18 each comprise a first flange 22, a connecting web 23, and a second flange 24. The flange 22 is generally rectangular and has an attaching means formed thereon. In the illustrated embodiment of FIGURES 1 to 3 the attaching means is a slide means 26 which defines, in cross-section, a C-shaped channel providing attaching lmeans cooperating with a tab on a mounting plate of one type of mop frame. Also located in the first flange 22 is a pair of depressed holes 27 adapted to receive selftapping screws which are adapted to be inserted through corresponding holes or slots in the mounting plate of a different type of mop frame affording attachment of the clip 18 to yvarious types of mop frames.

The web 23 is secured to the rst flange 22 in a position normal thereto and is adjacent the end of the sponge between the face side and the open ends of the slots.

The second flange 24 is secured to the web 23 and is in the form of prong means adapted to penetrate the sponge body at the slot to hold the sponge body to the attaching means. The prong means on the flange 24 is preferably formed with barbs to aid in retaining the prong means within the sponge body. In the illustrated embodiment the flange 24 is bifurcated forming a pair of thin pointed parallel spaced prongs 28 and 29 adjacent the outer end of which are barbs 31 and 32, respectively. The barbs 31 and 32 resist dislodgernent of the prongs from the slots in the sponge body, and the prongs 28 and 29 provide a sufficiently wide support for the sponge body during the mopping action to prevent tearing or any deleterious action on the sponge body.

The slots in the end of the sponge body may be formed at approximately the same moisture content as when the sponge is manufactured, sold and used, eliminating the expense of drying the sponge during manufacture of the mopheads. When the laminated abrasive mat 16 is added to the sponge head the elimination of the need for drying the sponge at all is of significant advantage.

FIGURE 4 illustrates a modification 36 of the clip 18 and on a first flange 37 thereof, instead of having the slide means for attachment, there is formed a tab 38 having a general T-shape in cross-section. This type of structure may afford attachment to only one type of mop frame but illustrates another type of attaching means which can be placed on the clip.

FIGURE 5 illustrates another embodiment 41 of the clip 18. In this embodiment only a pair of depressed holes 42 are formed in the first flange 43 to serve as the attaching means, and the second flange 44 is formed as a single prong rather than the preferred plurality of spaced prongs as characteristic of the clips 18 and 36. The two prongs which closely fit in the slots afford increased area contact to resist tearing.

The prong means have a length relative to the sponge body to minimize any tendency of the sponge body to bow in the central portion during use. The prongs do however permit longitudinal compression of the sponge body to fit the same on some mop frames and, as illustrated, lare spaced permitting the sponge body to be bent in the plane normal to the plane of the prong means.

Low density abrasive mat 16, a suitable form of which is described and claimed in U.S. Patent No. 2,958,593, may be adhered to the side 12 of the sponge by any suitable means. A particularly satisfactory technique is to embed it in one face of a sponge-forming cellulosic mass to a depth sufficiently to let the mass partially surround fibers in the interface, regenerate the cellulose, and convert the mass to sponge form, all as described and claimed in U.S. Patent No. 3,080,688. As best shown in FIGURE 2, it may be desirable to have the low density abrasive 16 extend less than the full depth of sponge body, thereby keeping it normally out of contact with the floor when the lower side or surface 13 of sponge body is being used.

Having thus described the present invention what is claimed is:

1. A sponge mophead adapted for removable attachment on a sponge mop frame having a mounting plate, said head comprising in combination,

a prismatic sponge body having two ends and a plurality of generally rectangular sides,

one of said sides being a face side adapted to be positioned adjacent a said mounting plate, said two ends each being formed with at least one thin slot which extends from a position in said end below said face side axially of said body parallel to said face side,

.a pair of generally U-shaped clips, adapted for securing a said b'ody to a said mounting plate, each said clip comprising a generally rectangular flange having one surface overlying said face Side of said body and having .attaching means thereon adapted for connection to corresponding means on a said mop frame mounting plate adapted to be positioned adjacent a surface of said flange opposite said one surface, a web portion joined to said flange and positioned normal thereto be adjacent one end of said body, and

prong means joined to said web portion and extending generally parallel to said flange and adapted to penetate said sponge body by fitting in said at least one s ot.

2. A sponge mophead as claimed in claim 1 wherein said ends are each formed with a plurality of spaced thin narrow slots and `wherein said prong means comprise spaced parallel thin fingers.

3. A sponge mophead as claimed in claim 2 wherein said fingers in each said clip extend less than half the length of the sponge body.

4. A sponge mophead as claimed in claim 1 wherein said prong means are formed with barbs which resist withdrawal of said prong means from said sponge body.

5. A sponge mophead as claimed in claim 1 wherein said attaching mea-ns on each said clip comprise slide means of sulicient dimension to .position and slidably engage cooperating tab means on a said mop frame mounting plate which extend longitudinally of said mounting plate and means dening mounting holes adapted to receive screws on a said mounting plate whereby said mophead can be attached to several types of mop frames.

6. A sponge mophead as claimed in claim 2 wherein said fingers are rectangular in cross-section with the fingers disposed in the same =plane and wherein said sponge body References Cited UNITED STATES PATENTS 2/ 1915 Helstrorn.

1/1934 Borden 15-244 5/1955 Vaughn 15-244 10/ 1962 Dryden 15-244 12/ 1967 Abler et al. 15-244 XR FOREIGN PATENTS 9/ 1964 Australia. 7/1938 Austria. 11/1961 France.

has a layer of low density brous lofty abrasive mat on 15 DANIEL BLUM, Prz'mmy Examiner.

another of said sides. 

